There seems to be a pretty wide consensus among people knowledgeable about Iran that the elections was stolen, but I do think it’s important to point out that this isn’t a universal view. Ken Ballen and Patrick Doherty, for example, write in the Washington Post that the result is similar to what their polls predicted. Ballen I don’t know, but Doherty’s a solid guy.
That said, Juan Cole raises a hugely important point of interpretation. Ballen and Doherty talk about how their mid-May poll showed Ahmadenijad with a 2–1 lead, about what the official results show. But they don’t mention the specific numbers. According to Professor Cole, “It found that the level of support for the incumbent was 34%, with Mousavi at 14%.” That seems like a 34–14 is very different from an official result in which Ahmadenijad’s support was in the sixties. In the domestic American context if you had an incumbent polling at 34 percent, you’d say he was in huge trouble no matter how badly his opponent was doing.